Mobile phone users are more interested in listening to digital radio through their handsets than watching mobile television services, according to research unveiled yesterday, and are only willing to pay about £5 a month for the privilege of catching up with their favourite shows on a phone's small screen.

The first major British trial of real broadcast mobile television was carried out by BT and Virgin Mobile among 1,000 users within London's M25 motorway. The results showed that while 59% rated mobile television as appealing or very appealing by the end of a six-month test, 65% said the same about digital radio. In terms of actual viewing and listening time, users watched an average of 66 minutes of television a week on their phone but listened to 95 minutes of radio.

Mobile telephone operators, desperate to make more money from their customers and having so far failed to persuade them to do more than talk and text, are clutching at mobile television as a potential money-spinner. The research, however, shows that most people would be willing to pay only about £5 for the service - half of what many in the industry were hoping.

While companies such as Vodafone and 3 are already offering mobile television, it uses up space on their expensive 3G networks and if 3G became very popular it could quickly clog up the airwaves, potentially leaving callers without a signal. The service that BT has developed, and which it hopes to sell to mobile phone companies across the world, uses a portion of the digital radio spectrum. So as well as live television stations revamped for mobile TV, handsets with the right receiver can also get digital radio stations.

As a result, the service may provide a new lease of life to radio companies as broadcasts over mobile phones also introduces the potential for interaction. Listeners would be able to press the equivalent of their TV's red button on their phone to get involved in radio quizzes and polls or to download music tracks.

"I would characterise it as radio [being] even more attractive than TV in the trial," said Emma Lloyd, managing director of BT's Movio business, which plans to offer a wholesale TV service to mobile phone companies from this summer. "We will be able to piggy-back on the attractiveness of digital radio and I don't think that is a negative thing; I see it as a positive thing because the UK leads the world in digital radio."

This Christmas, for instance, digital radios were again one of the top sellers among electrical goods. Part of the attraction of radio over mobile TV is also, she admitted, that "there are a lot of times in your daily life when it is not practical to look at a TV screen".

Participants in the trial were offered three channels a week from a selection including Sky News, Sky Sports News, E4, ITV2 and the Blaze music channel. The trial showed that while some viewers liked to dip in and out of the rolling news channels, many people used it to watch their favourite shows on ITV and E4 when out of the house.

While at home, participants used mobile television to continue watching when away from the set elsewhere in the house, while children used it to watch television in their bedrooms. Users preferred to watch whole programmes or news bulletins rather than specially prepared highlight channels. Mobile television was particularly popular with rail commuters with usage peaking in the mornings and evenings.

Backstory

Mobile television in Britain is available from Orange, Vodafone and 3, which all charge about £10 a month. All three use the firms' 3G networks, which cost billions to build but have so far given little return on investment. Streaming TV content over a mobile phone signal may be a quick way to make a return but it risks clogging up the network.

In contrast, BT's Movio's service uses a broadcast signal rather than a mobile phone network. It even works in areas without mobile phone coverage. It uses internet technology and part of the digital radio spectrum owned by Digital One, the national digital radio broadcaster controlled by GCap, to simulcast live TV channels to mobile phones fitted with a receiver.

The technology, called DAB-IP, works like a traditional TV and the first commercially available handset, made by Taiwan's HTC, is already rolling off the production line. As well as TV, the handsets can receive digital radio.

Virgin Mobile is angling for a period of exclusivity for the technology in Britain and will offer several channels in the summer. While mobile TV over 3G is available in several countries, Virgin Mobile looks set to be the first to offer real broadcast TV over DAB-IP.

Next week, O2 will announce results of a trial of another rival technology it has been testing in Oxford. Its service, which uses a Nokia-backed standard called DVB-H, relies on radio spectrum that will not be available in Britain until the analogue television signal is switched off in 2012.